Metropolitan Open Land and how it differs

Metropolitan Open Land is a London designation that gives strategically important open space the same policy protection as Green Belt, applied through the London Plan rather than through national Green Belt policy. The practical effect is that inappropriate development on Metropolitan Open Land is refused unless very special circumstances are shown, exactly as in the Green Belt, while the reasons for designating land in the first place are different and distinctly urban. Metropolitan Open Land policy catches developers who assume that because a site sits inside the built-up area, Green Belt style tests cannot apply.

They do. And in several boroughs the designation covers land that looks nothing like countryside.

What Metropolitan Open Land protects

The designation protects open land of strategic importance to London: large parks, commons, playing field complexes, cemeteries, reservoirs, allotment groups, golf courses and river corridors, including land well inside the urban area.

The policy purpose is about the structure of the city rather than preventing urban sprawl into countryside. Metropolitan Open Land is intended to contribute to London's overall open space provision, to provide a clear break in the built-up area, to serve recreation, nature conservation and food growing, and in some cases to contain features of national or metropolitan significance.

That is a different rationale from the five Green Belt purposes, which concern checking unrestricted sprawl, preventing towns merging, safeguarding countryside, preserving the setting of historic towns and assisting urban regeneration. The land in question is often surrounded by development on several sides, so sprawl is not the issue.

Why protection matches Green Belt policy

The London Plan directs that Metropolitan Open Land is afforded the same level of protection as Green Belt, which imports the national policy tests by reference.

So the decision structure is familiar. Development that is inappropriate is, by definition, harmful to the designation and should be refused unless very special circumstances exist that clearly outweigh the harm, with harm to openness given substantial weight. The categories of development that may be appropriate mirror the national list: buildings for agriculture and forestry, appropriate facilities for outdoor sport and recreation, cemeteries and burial grounds, limited extension or replacement of existing buildings, and limited infilling in specified circumstances.

Two differences matter in practice. The national grey belt concept introduced for Green Belt in the December 2024 Framework does not translate directly to Metropolitan Open Land, which is a London Plan designation with its own wording, so cite the London Plan policy and the current National Planning Policy Framework edition carefully rather than conflating the two. And the appropriate development categories drawn from agriculture read oddly on an inner London reservoir, which is why most real cases turn on outdoor sport facilities, replacement buildings and infilling.

The criteria for designation and dedesignation

Designation is a plan-making act carried out by the borough through its local plan, against criteria set in the London Plan.

The criteria concern strategic significance: whether the land contributes to the physical structure of London by being clearly distinguishable from the built-up area, whether it includes open air facilities particularly for leisure, recreation, sport, the arts, cultural activities, religious use, cemeteries or food growing that serve either the whole or significant parts of London, whether it contains features or landscapes of national or metropolitan significance, or whether it forms part of a chain of open spaces.

Dedesignation is correspondingly hard. It requires the borough to demonstrate through the local plan process that the land no longer meets the criteria, tested at examination, and the London Plan sets a high bar because the designation is strategic. A site-specific planning application cannot dedesignate land, and arguing at application stage that land should never have been designated is a weak point to lead with, although it can carry some weight where the designation is manifestly inconsistent with the criteria.

Development that may be acceptable

Four routes account for most permissions, and knowing which one you are in determines the evidence.

Facilities for outdoor sport and recreation that preserve openness, which is the largest category: changing pavilions, clubhouses, floodlighting, all-weather pitches. The test is whether the facility preserves openness and does not conflict with the purposes of including land in the designation, so the argument is about scale, siting, and whether the built element can be kept low and compact.

Replacement of an existing building, where the replacement must be in the same use and not materially larger, which makes accurate measurement of the existing building the foundation of the case.

Limited extension or alteration of an existing building, with the same measurement discipline.

Development that is inappropriate but supported by very special circumstances, which is the hardest route and the one requiring the fullest evidence base.

Where a scheme touches open space provision, an Open Space Assessment and, on residential schemes, a Play Space Assessment against the Greater London Authority standards will be expected alongside the policy case in the Planning Statement.

Openness assessment in an urban setting

Openness is the central concept and it is not the same as visual amenity, though the two are related.

The courts have treated openness as having both a spatial dimension, meaning the absence of built form, and a visual dimension. Volume, footprint, height and the duration of any impact all bear on it, and so does whether development is above or below ground.

In an urban setting the assessment has particular features. The baseline is often already partly developed, with a pavilion, car park or maintenance depot on the land, so the comparison is between the existing degree of openness and the proposed, not between a greenfield and a building. Enclosure by surrounding development does not reduce the protection, because the designation is about the land itself. And views from within the space matter as much as views into it, because the recreational function is experienced from inside.

Illustrative example: a sports ground in outer London designated as Metropolitan Open Land, with an existing 1960s single-storey pavilion of 300 m² footprint. A replacement clubhouse of similar footprint and height, sited on the same hardstanding, is a conventional replacement building case. A two-storey clubhouse of twice the footprint with a 60-space car park across the pitch edge is inappropriate development needing very special circumstances, whatever the sporting benefits.

Boundary disputes and plan reviews

Boundaries are drawn on the local plan policies map and the mapping is not always as precise as it needs to be.

Where a site boundary and the designation boundary appear to diverge, resolve it with evidence rather than assertion: the adopted policies map extract at the largest available scale, the predecessor plan's mapping, any inspector's report dealing with that boundary at examination, and a measured site survey overlaid on the designation. Mapping digitised from an older paper plan can be out by several metres, and on a narrow strip that matters.

The route to change a boundary is the local plan review. Monitor the borough's local development scheme for the review timetable, respond to the call for sites, and make the case at Regulation 18 and Regulation 19 stages with evidence against the designation criteria. That is a multi-year process, not an application strategy.

Checking the designation for a site

Three sources, cross-checked.

Start with the borough's adopted local plan policies map, which is the determinative source, and take an extract at the largest scale available. Then check the national planning data service, which publishes borough-supplied designation datasets and is useful for a quick screen but is only as current as the borough's submission. Then read the policy text itself in both the London Plan and the borough local plan, because some boroughs carry additional local designations such as Local Open Space or Sites of Importance for Nature Conservation over the same land, each with its own test.

Finally, read the site's planning history. Previous decisions and any appeal decisions on the land will show how the designation has been applied there, and appeal decisions are indicative of how inspectors have approached the issue rather than binding precedent. Other London designations worth checking at the same time include safeguarded wharves and waterside development in London, and the setting tests that can run alongside are covered in registered parks and gardens and the setting test.

This is general guidance, not legal advice; check the position with the borough and the current London Plan policy, or take advice from a qualified professional, before relying on it.